Mercury switch generator for electric fuzes



Nov. 14, 1961 H. E. RUEHLEMANN 3,008,416

MERCURY SWITCH GENERATOR FOR ELECTRIC FUZES Filed Feb. 25, 1955 27 1 :L K I \7' I, II III 1/ INVENTOR H. E. RUEHLEMANN ATTORNEYS United States The-invention described herein may be ma-nufactured .andusedbyorfor the Government :of the United States ref-America for governmental purposes without thepayanentof any royalties? thereon ortherefor.

,-'I he;.pres,ent inventionrelates to anaelectrostatic gen- 1 erator: and moresparticularly tona spin operated e1ectroestaticggenerator of -the type which employs. a globulexof *mercury; and .in which .themercury. performs a dual func- .-tion ofuactuating-switching contacts to interrupt a nor- .mal-lyclosedwircuit and concurrently therewithaactivating =an-open .circuit the-mercuryis forced throughv a-xporous diaphragm by centrifugal force fromonecontainer toanother container, and in which the mercury develops an electrical potential between one of :the switch contacts i-and the; generator terminal during the flow of the merrcury between the containers.

I .In. devices of thisgeneral character hereinbefore devised, it has been the usual practice to employ a substance such as mercury for generating an electrostatic charge as the mercury passes through a porous barrier and incertain other devices, mercury has been employed to open or close selectively switching contacts. In each of such devices, however, the mercury performs but a single function. and therefore at least two such devices would be required, each of the devices containing a quantity of mercuryawhich'functions independently and separately from the mercury in the other device.

The present invention possesses all of the advantages of the foregoing devices and none of the foregoing disadvantages. In accordance with a preferred embodiment .of the invention only-a single globule of mercury is employed. .This globule of mercury is normally retained within ,a chamberuntil forced therefrom through a porous zdia'phragminto a second chamber by centrifugal force applied to the envelope of which the chambers are formed. By providinga pair .of electrodes respectively in communicatiQnwith the two chambers and a conducting portion *of the first chamber in normal contact with-the mercuryythe "devicepe rforms'the function'ofa single pole switch in addition to generating an electrostatic poteriti'al as the mercury is "forced into'the second container, -as'-willhereinaftereappear more clearly as the description proceeds.

1 Oneaofithe objects of the present. invention is to; proon'denarnew. andoimproved;electrostatic generator having means for performing a: switching functiomas. theelectrostatic charge is generated.

Anotherraohject is to:providetafljsinglezzpoleaspin operated mercuryswitch in whichnew and improved means are provided for collecting a static charge generated by the zmercuryiv as the switch .pperates. ;in :response; to cantrifugal force applied thereto.

A still further object is a new and improved device for energizing and rendering effective the firing circuit of a spin type missile during the flight of the missile.

Still other objects, advantages and improvements will be apparent from the following description taken in connection with the accompanying drawing on which is shown the invention according to a preferred embodiment thereof.

Referring now to the drawing for a more complete understanding of the invention, there is shown thereon a =spin operatedmercuryswitch and electrostatic generator indicatedsgenerally -by.the numeral 10,,theswitch comprising an envelope, generally circular in. shape and formed. of a metallic portion 11 bonded to acylindrical glass POI'tiOIlLIZBS atr13 and disposedcoaxially there- =-with. :The metallic portionll has formed therein-anannular protuberance l4uwithi-n which is disposed a porous sintered -diaphragm 15-composed of .any suitable metal such, for example, asstainless steel to which the envelope is sealed at the portion'M thereof. A glass seal'16 having an electrode-17 .therein :isemployed to seal the end of the metallic portion of the. envelope thereby prov-idinga chamberls within-Which is disposed a copiousquantity of. mercury .19.

The other-end of the. envelope is-enclosed by'a cap or charge collector 21' sealed thereto -as at 22 substantially as .shown. The cap is composed of anymetal suitable for thepurpose and is "provided Witha terminal23 for :establishing an external electrical connection thereto. The capz21. and glass portion of the envelope comprise means forming, a chamber 24, into which the mercury is forced by. centrifugal forceas it passes through the diaphragm 15.

The device of the present invention is suitable for many useful purposes, such, for. example, for use with the circuitillustrated for firing an electroresponsive detonator :25 upon ractuationmof the impact switch 26 after the [condenser 27 has been charged by the device. The elecvtrode 17 is connected :by conductor 28 to the detonator :25. and to the impact switch 26. The metallic portion 11 of -thetenvelope is connected by the conductor 29 to the detonator 25 and tothe condenser27 and the terminal .23 is connected to the other plate of the condenser 27 and to the. impact switch 26 by the conductor 30.

The operationof the device will now be described. Let

itrbe assumed, by way :of example, thatthe mercury :switch and electrostatic generator 10 is mounted within a spin type missile in such a manner that the mercury will be forced from chamber 18 through porous diaphragm 15 into chamber 24 by centrifugal force during the. flight of the missile and that chamber 18 is initially :provided-with acopious quantity of mercury. It-Willrbe-noted that with the mercury in chamber 18 as illustrated, the detonatorZS is normally-shortedby the mercury. As-mercury is forced through: the porous -diaphragm.15-by centrifugal force frorn'chamber 18 into chamberld anelectrostaticcharge is developed thereby. :This :charge is collected on .the charge collectorll and :applied to.condenser-27. When sufiicient mercury has passed through porous diaphragm 15 to interrupt thecircuitbetweemthe metallic-portion 11 TOf theenvelope and electrode:17, the short is removed from thedetonator .25, the flowof, droplets of-emercury into chamber Maud en- .igaging cap .21. causing an electrostatic. charge to be developed suflicient to charge condenser' Z7. When this occurs, wthe missileisrarmed. ,-As the missile-strikesa target, imr-pact; switch -.-26 is closed thereby. closing .afiring ,circuit from. the charged condenser to the detonator. .and, firing the detonator.

-,Byeernployingt a porous .diaphragmin .the .manner. disclosed-, herein,-. the flow-of mercury from..chamber 18.to ;chamber-24.;-isretarded; and the: switch, therefore is. made slow-acting whereby the missile is not armed until a predetermined time has elapsed since it was launched in flight. Furthermore, by retarding the flow of mercury between the chambers in the manner shown, the switch is made non-responsive to shocks or sudden jolts and thereby rendered safe in handling and during transportation. Premature arming and firing are thus prevented.

Whereas'the invention has been described in detail with respect to arming and firing means for a spin type projectile in which the electrical energy required for operating the detonator is generated by a sustained application of centrifugal force applied to the mercuric element of the device during flight, it is not so limited as it may be advantageously employed for various other purposes and in other combinations with circuit components other than those illustrated in which -a switching function concurrently with the generation of an electrostatic potential is advantageous. y

Obviously many modifications and variationsof the present invention are possible in thelight of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed as new and-desired to be secured by Letters Patent of the United States is:

l. A spin operated electrostatic generator ofthe character disclosed comprising an electrical conducting envelope of circular configuration 'having an electrode disposed therein, means supporting said electrode in sealed relation to one end of said envelope and insulated therefrom, a second cylindrical envelope composed of insulating material secured at one end thereof to the first-named envelope coaxially therewith, a charge collector composed of electrical conducting material sealing the other end of said insulated envelope, a porous diaphragm disposed transversely within the other end portion of said conducting envelope thereby forming a chamber Within which a quantity of mercury is disposed sufiicient to normally engage said electrode, said second envelope forming a second chamber between the diaphragm and said charge collector whereby the conducting envelope is normally electrically connected to the electrode by the mercury and an electrostatic charge is developed between the metallic envelope and the charge collector as dropletsvof mercury are forced through the diaphragm by centrifugal force continuously applied thereto. i p

2. A mercury. switch gst-atic generator of ,the character disclosed comprising a circular envelope composed of electrical conducting material and a second envelope composed of insulating material, secured theretoin coaxial relation, a porous metal diaphragm disposed transversely 40 trical conducting envelope, and a conducting cap sealed to the other end of the non-conducting envelope fortcol-t lecting a charge thereon as the mercury is forced in droplets through the diaphragm by centrifugal force as the droplets of mercury come into electrical conduct with the cap. 7 v a 2 V 3. A mercury switch generator for an electric fuze comprising a cylindrical envelope having an electricalconducting portion and an insulating portion along the, length thereof, a porous metal baflle member arranged transversely within the envelope adjacent the intersection of ,the conducting and nomconducting portions thereof, an insulating seal closing the'otherend of-said conducting portion of the envelope and forrning a charnr n her therein a quantity of mercurywi-thin saidfchamber, 7

an electrode carriediby said seal for'establishing an electrical connection through the mercury with said conducting portion ofthe envelope, a charge collecting cap sealed 7 to the outer end of the non-conducting portion of said envelope and having means for establishing an electrical is rendered effective to fire the detonator-by: the charge on said condenser upon closure of the switch. 1

4. A spin operated mercury switch of the character disclosed comprising an envelope, means for sealing said envelope, a porous baflle 'disposed'transverselylof said envelope therebyto form -two chambers, a quantity of mercury within the'first of said chambers, an electrode in contact with said. mercury, that portion of the envelope a forming said first chamber being 'elect'roconductive thereby providing a switching *mechauism normally closed :by said mercury, and a charge collecting device the second chamber and insulated from said electroconductiveportion for collecting a static charge as droplets of mercury flow through said bame in response to a sustained force caused by said spin.

5. A spin actuatable' mercury electrostatic generator for arming the fuze of a projectile and comprisingan elongated, sealed envelope having onepiortionxthereof electrically conducting and the other portion non-'con-s ducting, a porous diaphragm arranged transversely a said envelope and carried thereby forming two chambers associated with said conducting and non-conducting por tions respectively, a quantity of mercury'rior'mallydis posed within'said conducting chambenan electrode arranged within said'conductiugch'a-mbcr adjacent but not,

in contactwith said diaphragm'whereby the conducting portion of the envelope and electrode are normally shorted by the mercury, and ach-ar'ge collector on the other-end of the non-conducting envelope and disposed withthe chamber formed thereby for collecting, an electrostatic charge thereon as droplets'of mercury are forcedthrough spin of the projectile;

the diaphragm by asustained force applied thereto by the ineffective electroresponsive detonator connectedacross said electrode and said conducting portion of the casing 7 and being rendered effeotive as the mercury is forced through the diaphragm.. r 5

7. A claim according to claim 6 including a nor-mally inefiective condenser of sufficient capacity to fire said detonator connected across said conducting poption of the casing and said charge. collector whereby the condenser is charged and rendered effective as the mercury is forced --throughrthel .diaphragm and engages the chargelicollect'or. 8. Aclaim according to claim 7 in which a' normally openifi'ri'ng switch is connected across said electrode and a charge collector thereby to fire the deton ator from the charged condenser as the switch is UNITED STATES r ATENrsif' t 2,414,836 Rickmeyerhuhaglhu flh Jan. 2s,"1947 A claim according to claim Sincludingan initially Cited 'in'the file of p tent A 

